Search Results (3,045)

Retinal ischemia is a key factor in the progression of vision-threatening ocular diseases, including central retinal artery/vein occlusion, exudative age-related macular degeneration (eAMD), and proliferative diabetic retinopathy. This study investigates the effects of paeoniflorin along with its related neuroprotective molecular pathways in the treatment of retinal ischemia. Free radical or ischemic-like damage was induced by incubating retinal pigment epithelium (RPE) cells for 24 h with 1 mM hydrogen peroxide (H₂O₂) or by subjecting retinal neuronal cells to 8 h of oxygen–glucose deprivation (OGD). Both treatments caused significant cell loss. Treatment with paeoniflorin significantly increased cell viability at 0.5 mM in both cell types. In a Wistar rat model of retinal ischemia and reperfusion (I/R) elicited by sustained high intraocular pressure (HIOP), pre-treatment with 0.5 mM paeoniflorin mitigated the ischemia-induced decline in ERG b-wave amplitude, reduction in whole and inner retinal thickness, loss of fluorogold-labeled retinal ganglion cells, and formation of apoptotic cells. Meanwhile, paeoniflorin effectively downregulated pro-neovascular mediators β-catenin, hypoxia-inducible factor 1-alpha (HIF-1α), vascular endothelial growth factor (VEGF), and the pro-inflammatory/angiogenic biomarker angiopoietin-2 (Ang-2), producing effects similar to the Wnt/β-catenin inhibitor (dickkopf-related protein 1), anti-angiogenic pigment epithelium-derived factor (PEDF), and anti-VEGF Avastin (bevacizumab). These findings suggest that paeoniflorin may protect against retinal ischemia through its anti-inflammatory, anti-neovascular/angiogenic, antioxidative, and neuroprotective properties. Full article

Gas bearings are attractive for sustainable, high-speed, and cryogenic applications, where gases replace liquid lubricants. This study numerically analyzed hybrid gas journal bearings lubricated with hydrogen, nitrogen, air, and helium, and quantifies the impact of circumferential micro-grooves. The compressible Reynolds equation was solved by the finite element method with constant-flow valve restrictors, while Gauss–Seidel iterations were used for convergence. The model was verified against published theoretical and experimental data with maximum deviations below 6%, and mesh independence is confirmed. The parametric results show that the gas type and texturing jointly controlled static and dynamic performance. Helium (highest viscosity) yielded the largest minimum film thickness, whereas hydrogen (lowest viscosity) attained higher peak pressures at a lower film thickness for a given load. Grooves redistributed pressure and reduced both the maximum pressure and the minimum film thickness, but they also lowered the frictional torque. Quantitatively, the hydrogen-lubricated grooved bearing reduced the frictional torque by up to 50% compared with the non-grooved air-lubricated bearing at the same load. Relative to air, hydrogen increased stiffness and damping by up to 10% and 50%, respectively, and raised the stability threshold speed by 110%. Conversely, grooves decreased the stiffness, damping, and stability threshold speed compared with non-grooved surfaces, revealing a trade-off between friction reduction and dynamic stability. These findings provide design guidance for selecting gas media and surface texturing to tailor hybrid gas journal bearings to application-specific requirements. Full article

Background: This case report aimed to quantify dental, alveolar, and skeletal changes, periodontal health, and sleep quality after treatment with a tooth-borne rapid palatal expander (RPE) in a young adult with bilateral posterior crossbite due to transverse maxillary deficiency. Tooth-borne RPE is typically indicated during the prepubertal or pubertal growth phases; however, some post-pubertal or young adult patients may still present with incomplete maturation of the midpalatal suture—the so-called “gray zone.” In clinical practice, treatment decisions should ideally consider multiple skeletal resistance areas (the zygomaticomaxillary buttress, the pterygomaxillary junction, the nasal aperture pillars), although midpalatal suture assessment often remains central to case selection. Methods: A 19-year-old male patient presented with a skeletal Class III tendency, dental crowding, and anterior and bilateral posterior crossbites, accompanied by snoring and breathing difficulties. The patient declined surgical- and miniscrew-assisted RPE. Cone-beam computed tomography (CBCT) scan revealed incomplete midpalatal suture maturation. Based on periodontal evaluation, a conventional tooth-borne RPE was chosen. Pre- and post-expansion CBCT scans were used to evaluate dental, skeletal, and periodontal outcomes. Results: After one year of treatment, bilateral posterior crossbite was successfully corrected. Buccal bone thickness showed a slight reduction only on the upper left first molar (from 1.2 mm to 0.9 mm), without evidence of dehiscence or fenestration. A 2° increase in the dental tipping angle (DTA) was observed on both molars, and the palatal alveolar angle (PAA) increased by 3°. Sutural separation expanded from 0.32 mm to 7.82 mm. The Midpalatal Opening Related to Expander Opening (MORE) factor was 0.54, indicating a predominantly skeletal response. Periodontal health remained stable, and CBCT analysis confirmed increases in intermolar width (from 36.08 mm to 50.02 mm) and palatal maxillary width (from 28.04 mm to 34.5 mm). A reduction in the Pittsburgh Sleep Quality Index (PSQI) from 7 to 3 was observed, though this finding should be interpreted cautiously due to its subjective nature and the absence of objective airway measurements. Conclusions: The present case report suggests that tooth-borne RPE may represent a viable and minimally invasive option for correcting posterior crossbite in carefully selected young adults with incomplete midpalatal suture maturation. However, the findings are limited to a single case with short follow-up and should be regarded as hypothesis-generating rather than conclusive. Full article

Hair loss and scalp dysfunction are prevalent concerns with limited non-medicinal long-term solutions. Growth factors and plant-derived extracellular vesicle (EV) represent promising regenerative approaches. In this exploratory randomized controlled trial, 60 healthy adults (18–60 years) were randomly assigned into five groups: (A) placebo; (B) base formula with 0.1% caffeine and panthenol; (C) base + recombinant Fc-fusion long-acting insulin-like growth factor-1 (rIGF-1) and fibroblast growth factor-7 (rFGF-7); (D) base + Centella asiatica (C. asiatica) EV; and (E) base + rIGF-1, rFGF-7, and C. asiatica EV. Participants applied their assigned product once daily for 56 days. Scalp and hair parameters, including sebum content, hair length, thickness, density, and hair loss, were assessed at baseline and Days 14, 28, 42, and 56. The combination of C. asiatica EV with rIGF-1 and rFGF-7 (Group E) showed the greatest improvements across all endpoints, including significant increases in hair thickness, density, and length, and a reduction in sebum content and hair loss by Day 56 compared with placebo. The results support further study of topical use of C. asiatica-derived EV with recombinant long-acting growth factors as a novel, naturally derived, cosmetic intervention for scalp and hair care. Full article

Myo-inositol (cis-1,2,3,5-trans-4,6-cyclohexanehexol) (In) was incorporated into rigid polyurethane/polyisocyanurate (PU/PIR) foams to investigate its effect on the degradation and performance properties of the foam, as well as its structure. The parameters studied included production temperature, processing times, strength, absorbency, and flammability. The foams were aged (degraded) in a special degradation chamber. The test results indicated the effect of myo-inositol on the foam properties. The addition of In caused a reduction in the cell diameter of the foams (measured in both directions). Absorptivity and water absorption decreased. The compressive strength of the foams increased and the flammability decreased (increased retention and decreased burning rate). As a result of foam degradation, the thickness of the degraded foam layer containing 13 wt.% myo-inositol (In13_D) increased by approximately 30% compared to the reference foam (In0_D). Full article

This study investigates the influence of sevoflurane and desflurane on the electrochemical behavior of the Fe(III)-acetylacetonate (Fe(acac)₃) complex. Using cyclic voltammetry (CV), we demonstrate that while Fe(acac)₃ exhibits reversible redox behavior in an oxygen-free environment, the presence of dissolved oxygen renders the system irreversible, leading to the formation of a thick, reddish film on the electrode surface upon potential cycling. Notably, the addition of sevoflurane and desflurane restores the electrochemical reversibility and dramatically inhibits this film formation. Raman spectroscopy of the resulting films confirmed structural changes which are consistent with this inhibiting action. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis reveals that the iron in the film remains predominantly in the Fe³⁺ oxidation state even after prolonged electrochemical reduction cycles. These findings suggest that the anesthetics act by inhibiting the interaction between the Fe(acac)₃ complex and oxygen, likely through a spin–decoherence mechanism. This work highlights the critical role of anesthetics in modifying the electrochemical behavior of metal-oxygen complexes, with potential implications for sensing, electrocatalysis, and bio-oriented systems. Full article

Background/Objectives: Accurate prediction of reproductive outcomes remains a key challenge in assisted reproductive technologies (ARTs). While embryo quality assessment has been extensively studied, endometrial receptivity has received less attention despite its critical role in implantation. Endometrial compaction (EC), i.e., the reduction in endometrial thickness between ovulation and embryo transfer, has been proposed as a potential predictor, but the current literature data is inconclusive. This study aimed to develop and validate a novel implantation predictor (IMP), based on extended assessment of endometrial shape and dynamics, which would be useful in determining reproductive success. Methods: The study analyzed data from 61 couples undergoing infertility treatment at the Kriobank Clinic (Białystok, Poland) between December 2021 and February 2025. Endometrial measurements were taken at the day following the ovulatory peak and on the day of embryo transfer. A set of normalized parameters describing endometrial dimensions was proposed and their changes over time measured. Based on the obtained data, a multivariable logistic regression model was constructed to create the IMP. Results: The proposed model demonstrated high predictive power for implantation, with an AUC of 0.839 (95% CI: 0.739–0.938). Statistically significant differences in IMP values were observed between the pregnancy and no-pregnancy groups (p < 0.0001). Quartile analysis showed that implantation rates increased from 6.25% in the lowest IMP range to 93.3% in the highest, confirming the model’s strong predictive power. In the study group, the model is capable of predicting a quarter of cases in which implantation will almost certainly occur and another quarter in which implantation will almost certainly not occur. Conclusions: This study introduces a novel predictor (IMP) of implantation based on an extensive assessment of endometrial compaction, which may be used in predicting reproductive success. The findings show the importance of considering endometrial receptivity in ART success. They also indicate that integrating IMP with existing approaches may substantially improve predicting reproductive success. Full article

Additive manufacturing (AM) has emerged as a promising technology for producing low-cost, customized tooling, particularly for prototyping and small-series injection molding. However, the inherent surface roughness and anisotropic properties of 3D-printed parts pose significant challenges for their direct use as functional mold inserts. This study investigates the effectiveness of various post-processing techniques on 3D-printed plastic inserts made from polyamide 12 (PA12) and glass bead-filled PA12 (PA12GB). The primary objective was to evaluate the impact of these surface treatments on the functional properties and service life of the mold inserts. A comprehensive analysis was conducted, including a detailed characterization of roughness using a confocal microscope, cross-sectional analysis to determine layer thickness, and tribological tests employing the ball-on-disc method to assess wear resistance. The study employed a modular injection mold and tested a range of surface finishing processes, including PostProcess Suspended Rotational Force (SRF) technology, metal decomposition coatings from HVM Plasma, and various methods from DyeMansion (Powershot S and Powerfuse). Results show a significant reduction in surface roughness across all methods. Notably, the vapor-based Powefuse treatment from DyeMansion achieved a surface roughness (R_a) of 1.2797 μm, which is below the typical R_a value of 1.6 μm for conventional metal molds, thereby making it suitable for high-quality molding applications. The tribological analysis provided critical insights into the durability and wear resistance of the treated surfaces, supporting their potential for extended use. This research validates the potential of specific post-processing methods to transform AM parts into functional tooling, enabling cost-effective and rapid prototyping in the plastics industry. Full article

This study investigates the displacement behavior of excavations under asymmetric loading conditions and proposes optimized support design strategies from the perspective of displacement control. Physical model tests reveal that, in excavation projects under eccentric loading conditions, the retaining structure as a whole tends to deform toward the non-surcharge side rather than following the conventional symmetric deformation pattern. Displacement increases nonlinearly with surcharge intensity, but the growth rate diminishes as the load further increases due to localized surcharge effects and structural restraints. Numerical analyses further demonstrate that increasing embedment depth and wall thickness effectively mitigates lateral displacement, although a marginal effect is observed beyond critical thresholds. For instance, at an embedment depth of 12 m (twice the excavation depth), maximum lateral displacement decreases by nearly 50%, and when combined with a wall thickness of 13 cm and a depth of 14 m, the reduction reaches approximately 90%. These findings establish a quantitative basis for deformation control in excavations subjected to asymmetric loading and guide the efficient optimization of retaining systems. They enhance design reliability and construction efficiency, offering practical value for improving safety, performance, and overall project economy. Full article

This study investigates the influence of current density distribution on the hardening behavior of 20GL cast steel during electrolytic plasma processing (EPP). Experimental and numerical methods were combined to establish the relationship between discharge dynamics, heat flux, microstructural transformation. Electrolytic plasma hardening was carried out at cathodic voltages of 150 V and 250 V in a 20% Na₂CO₃ solution. The transient evolution of current density was analyzed using a 3D COMSOL Multiphysics model incorporating a vapor–gas shell (VGS) represented as a distributed impedance layer with realistic conductivity and permittivity. High-speed video confirmed that microdischarges preferentially initiate at sample corners, where modeling also predicts local current concentration and heat flux up to 12 MW/m². Experimental current density values (3–4 × 10⁴ A/m²) showed good agreement with the simulations. Microhardness tests revealed that increasing voltage from 150 V to 250 V increases the thickness of the hardened layer (from ~250 µm to ~600 µm) and raises surface hardness (up to 750 HV), while polarization tests showed a 40% reduction in corrosion rate. The results highlight that current density distribution governs the non-uniformity of thermal effects and surface strengthening during EPP, emphasizing the importance of electrode alignment and VGS stability for uniform hardening. Full article

Through employing WO₃ as a precursor, we successfully deposited a complete and continuous WC coating onto the surface of diamond particles by means of the salt bath method. Initially, a tungsten (W) layer forms on the diamond surface, which gradually transitions to a tungsten carbide (WC) coating as either the temperature is elevated or the duration of the process is prolonged. A thorough thermodynamic analysis was conducted to investigate this phase transition mechanism. At a lower synthesis temperature of 1000 °C, significant differences were observed in both the thickness and phase composition of the coatings formed on the (100) and (111) crystal planes of diamond. Specifically, the coating on the (100) plane exhibited earlier growth compared to that on the (111) plane, with WC phases appearing sooner within the coating’s composition. However, as the synthesis temperature increases, these differences in both thickness and phase composition between coatings on different diamond crystal faces tend to diminish, leading towards convergence. Furthermore, a detailed kinetic analysis of the coating growth process was conducted. It was found that the reduction reaction of carbon on WO₃ led to the formation of the W coating, and the diffusion of carbon in the W coating resulted in the formation of the WC coating. The diffusion of carbon in the coating ensured its continuous growth, providing deeper insights into the mechanisms governing the deposition and transformation processes. Full article

The development of electro-thermal textiles has attracted growing interest as a promising approach for active thermal management in wearable systems. Metallic-coated fabrics can efficiently generate heat through the Joule effect; however, their long-term performance and safety are severely limited under perspiration due to metal ion release and corrosion. To overcome these challenges, this study introduces a Parylene-C encapsulation strategy for copper-coated polyethylene terephthalate nonwovens (CuPET) using a chemical vapor deposition (CVD) process. The conformal, biocompatible Parylene-C films (thickness 4–16 μm) act as effective protective barriers while preserving the porous textile structure. Morphological and comfort analyses demonstrate a controlled reduction in air permeability from 3100 to 1100 L·m⁻²·s⁻¹, maintaining acceptable breathability. Electro-thermal measurements reveal rapid and uniform heating, reaching 40–45 °C within 2 min at 2 V, and the addition of a thermal insulation layer further enhances the Joule heating efficiency, increasing the steady-state temperature by approximately 6 °C. ICP–OES results show an ≈80% reduction in copper ion release (from 28.34 mg·L⁻¹ to 5.80 mg·L⁻¹) after artificial sweat exposure. This work demonstrates a scalable encapsulation route that effectively balances sweat protection, electrical stability, and thermal performance, paving the way for safe, durable, and actively heated smart textiles for advanced thermal insulation applications. Full article

The mechanical response and failure behavior of high-pressure frozen ice are essential to the technological progress in drilling thick polar ice sheets, but current research primarily focuses on non-pressure-frozen ice. In this paper, ice specimens with a cylindrical geometry were fabricated at −20 °C, applying freezing pressures across a range of 10 to 40 MPa with a 10 MPa interval. Their mechanical properties were investigated through triaxial compression tests under axial loading conditions and were compared with the results obtained at −10 °C. The results indicate that, with increasing freezing pressure, the samples transitioned from a failure state of interlaced cracking to a highly transparent state. The failure behavior observed in the specimens was characterized as ductile, as evidenced by the deviatoric stress–axial strain relationships. Moreover, the peak deviatoric stress exhibited a non-monotonic dependence on freezing pressure, with an initial rise from 9.59 MPa at 10 MPa to a peak of 14.37 MPa at 30 MPa and a subsequent decline to 10.12 MPa at 40 MPa. All specimens reached a relatively stable residual state at 5% axial strain, with residual deviatoric stresses ranging from 4.13 to 5.71 MPa. A reduction in freezing temperature from −10 °C to −20 °C can effectively enhance both the peak deviatoric stress and the residual stress of high-pressure frozen ice under triaxial shear conditions. All peak tangent modulus values, ranging from 1.61 to 2.93 GPa with an average of 2.2 GPa, were observed within 0.7% axial strain and exhibited mild fluctuations with increasing freezing pressure. These findings provide a more robust mechanical foundation for drilling research and operations in extremely thick polar ice caps. Full article

Soursop fruit of Annona muricata L. is a delicious tropical fruit with several medicinal properties. Previous research focused mainly on postharvest fruit development. This study aims to study the changes during preharvest development and ripening of soursop fruit. Flowers were tagged, and fruit samples were collected at different developmental stages based on days after take-off (DAT). The weight changes, flesh firmness, ethylene production, respiration rate, pH, total acidity (TA), total soluble solids (TSS), and cuticle thickness were measured. An increase in respiration rate from 7 to 41 mL CO₂ kg⁻¹ h⁻¹, a weight increase from 20 to 600 g, a pH decrease from 6.5 to 3.8, a firmness reduction from 20 to 0.8 N, and a cuticle thickness change from 6 to 4 μm were recorded. During preharvest, two different growth periods were recorded: a continuous increase in respiration rate and TSS, a slow decrease in TA, and a constant pH. Further, an increase in firmness was observed until 75 DAT and a decrease after 90 DAT. Cuticle thickness did not show significant changes. During postharvest, soursop fruit showed a sharp increase in TSS, TA, and a notable decrease in pH and firmness. A climacteric peak was recorded six days after harvest with a short postharvest shelf life. It was concluded that the fruit showed the typical behavior of a climacteric fruit. Also, future investigations should focus on the period between 105 and 120 DAT to identify the optimal harvest periods due to the relatively short postharvest shelf life. Full article

Hydrogen peroxide (H₂O₂) is a clean and environmentally friendly oxidant. At present, as an alternative to the conventional industrial procedure, namely, the anthraquinone method, a clean H₂O₂ production method is desired. The construction of an artificial photosynthetic system in which H₂O₂ can ideally be prepared from water and dioxygen (O₂) is a promising approach. In such a system, an organic p-n bilayer comprising zinc phthalocyanine (ZnPc, p-type) and fullerene (C₆₀, n-type) acts as a photocathode capable of O₂ reduction to H₂O₂, where loading gold (Au) onto the C₆₀ surface is necessary to achieve the corresponding reaction. However, the enhancement of the photocathodic activity of the organic p-n bilayer for H₂O₂ formation remains a critical issue. In this study, the effect of the thickness of an organo-bilayer (organo-photocathode) on photocathodic activity for H₂O₂ production was investigated. When both ZnPc and C₆₀ were thin (approximately 10 nm each in thickness), the photocathodic activity of the ZnPc/C₆₀ organo-photocathode was approximately 3.4 times greater than that of the thick ZnPc/C₆₀ bilayer (i.e., ZnPc = ca. 70 nm and C₆₀ = ca. 120 nm). The thin ZnPc/C₆₀ bilayer exhibited a built-in potential at the p-n interface, where efficient charge separation occurs, resulting in a high concentration of electrons available for O₂ reduction. Full article